>>>>> "rw" == Ross Walker <rswwal...@gmail.com> writes:
rw> Barriers are by default are disabled on ext3 mounts...
http://lwn.net/Articles/283161/
https://bugzilla.redhat.com/show_bug.cgi?id=458936
enabled by default on SLES. to enable on other distro:
mount -t ext3 -o barrier=1 <device> <mount point>
(no help if using LVM2)
rw> A lot of decisions in Linux are made in favor of performance
rw> over data consistency.
yes, which is why it's worth suspecting knfsd as well. However I
don't think you can sell a Solaris system that performs 1/3 as well on
better hardware without a real test case showing the fast system's
broken.
The fantastic thing to my view (and I'm NOT being sarcastic) is that,
if the fast system really is broken, you've the option of breaking ZFS
to match its performance (by disabling the ZIL). And after you've
done this, ZFS is still ahead of the old system because your cheat
hasn't put you at greater risk of corrupting the whole pool, while the
other system's cheating _has_. ...ZFS may still be more fragile
overall, but as a tradeoff, it's interesting.
But having this choice puts you in the position of really wanting to
know for sure if the other system's broken before you cripple your
own system perhaps destroying your reputation...
when you find out some ``unfair'' corner case was rescuing the old
system: ex. suppose contiguous journal doesn't get reordered by the
drive, and disk write buffers still get flushed if OS crashes which
turns out to be the common failure mode, not cord-yanking.
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